given a array of numbers, using Array.reduce return an array of uniques numbers

array_reduce_unique_numbers.js

function unique(array) {
    return array.reduce(function(acc, item){
        if(!acc.find(function(element){ return element === item; })){
            acc.push(item);
        }
        return acc;
    }, []);
}

var numbers = [1,1,2,3,4,4];

console.log(unique(numbers)); // [1,2,3,4]